Researchers at the University of Seoul have developed a folded lens system by using metasurfaces to reduce the volume of cameras.
Current lens systems, created by stacked refractive lenses, cannot be made thinner due to the empty space between lenses and the volume of each lens.
The researchers have developed a lens system that uses metasurface folded optics to overcome these issues, arranging metasurfaces horizontally on a glass wafer with direct light exposed along multifolded paths inside the substrate.
This design creates a significantly thinner lens system, with a thickness of 0.7mm, delivering quasi-diffraction-limited imaging quality with a 10 degrees field of view at an operational wavelength of 852 nanometres.
These “folded nano optics” could lead to much slimmer camera designs, no longer restricted by the empty spaces between individual lenses that are needed to guarantee an optical path length to achieve the desired effective focal length (EFL), creating a lens system that is twice as thin relative to the EFL.